EUNICE, N.M. (AP) — The Nuclear Regulatory Commission (NRC) on Monday began a special inspection at the Urenco USA uranium enrichment facility in southeastern New Mexico following an incident last month.

NRC officials said the April 21 incident involved the operation of a crane near a building that handles uranium hexafluoride without the required safety controls present.

They said there are concerns about safety protocols at the site and that warrants additional NRC inspection as it involves a breakdown of controls designed to prevent chemical, radiological and criticality hazards, which are the primary concern at U.S. fuel cycle facilities.

Two similar events last year at the Urenco USA facility prompted the NRC to propose a $70,000 civil penalty.

Inspectors from the NRC’s Region II office in Atlanta are at the Urenco USA plant for the next days.

They plan to assess the effectiveness of previous corrective actions taken by the facility to implement safety controls during construction activities and evaluate the appropriateness of the company’s overall response.

The inspection team will document their findings and conclusions in a public report that’s usually issued within 45 days of the inspection’s completion.